Clogs are a common problem in any device in which flowable materials flow through conduits and narrow passages. Examples of conduits in which clogs occur include drains of plumbing fixtures such as sinks, toilets, bathtubs and showers. Additional examples of conduits in which clogs can occur are automobile radiators/cooling systems, heat exchangers and marine engine cooling systems (outboard, inboard and inboard/outboard), especially those that use seawater for cooling.
One method for cleaning clogs in drains involves the use of a cable drain tool, such as a snake. However, tools such as these may damage plumbing fixtures and may prove difficult to use in some situations such as sinks and bathtubs with drains having narrow passages and/or a series of bends. Another method for cleaning clogs involves the use of high pressure devices such as a jetter, however, such devices may rupture plumbing joints.
A further method for cleaning drains includes using chemicals including caustics and acids. This method has drawbacks in that many types of chemicals may be highly detrimental to plumbing systems and plumbing fixtures and may cause personal injury and/or destroy metal fittings. Additionally, caustic chemicals may damage PVC pipes and acids may damage porcelain.
Although chemicals, abrasives, disinfectants and other agents may be used to remove grease, scale, bacteria, hair and other forms of material which block flow through various types of conduits, a limitation of these chemicals is their need to reach the surface of the conduit affected by the contamination in a uniform and effective way and to stay in contact long enough to be effective. The effect of gravity alone tends to force the chemical or agent to the lower surface of the conduits, leaving upper surfaces untouched and untreated. Mechanical methods, e.g., jetters, are sometimes employed to introduce cleaning solutions into contaminated conduits, but these tend to utilize very active chemicals or agents and reduce the contact time with the contaminated surface. Furthermore, such methods cannot negotiate many types of turns and traps in typical conduit installations.
Devices which manually apply pressure and vacuum pulses have been developed. Examples of such devices are described in U.S. Pat. Nos. 5,664,284; 5,193,245; 5,105,504; and 4,933,017, which are incorporated herein by reference. These devices have proven successful in clearing clogs in a wide variety of applications.
U.S. application Ser. No. 10/991,688 filed Nov. 18, 2004, which is incorporated herein by reference, discloses a modification of the devices in the above-noted patents in which an operator can variably control the amount of pressure and/or vacuum through the use of a controller mounted near the distal end of the hose of the device.
The above-noted devices may require the operator to move a control handle or lever back and forth from the pressure position to the vacuum position. The operator may thus manipulate the lever/handle too quickly or too slowly for effective wave action to be produced in the conduit. Also, to maximize the pressure or vacuum produced, the control lever/handle needs to be held tightly against the stop at the end of travel in either the pressure or vacuum directions. It would be desirable to eliminate the reciprocating action of the control lever/handle of such devices.